There aren't any true stone circles on Mann. Meayll Hill is often misinterpreted as a stone circle, but there aren't any bridges nearby. The Braaid is another non-stone circle that springs to mind. No bridges here either though.

A possible contender might be Cronk Karran, which is a circular setting of stones. There's no bridge as such nearby, but you have to navigate an Indiana-Jones-esque set of chasms to get to it. These might be described as land bridges.

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